package com.gatherlife.manager.utils;


import java.io.IOException;
import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

public class DESUtil {

	private final static String	DES	= "DES";

	/**
	 * Description 根据键值进行加密
	 * 
	 * @param data
	 * @param key
	 *            加密键byte数组
	 * @return
	 * @throws Exception
	 */
	public static String encrypt(String data, String key) {
		try {
			byte[] bt = encrypt(data.getBytes(), key.getBytes());
			String strs = new BASE64Encoder().encode(bt);
			return strs;
		} catch (Throwable e) {
			throw new RuntimeException(e);
		}
	}

	/**
	 * Description 根据键值进行解密
	 * 
	 * @param data
	 * @param key
	 *            加密键byte数组
	 * @return
	 * @throws IOException
	 * @throws Exception
	 */
	public static String decrypt(String data, String key) {
		try {
			if (data == null) {
				return null;
			}
			BASE64Decoder decoder = new BASE64Decoder();
			byte[] buf = decoder.decodeBuffer(data);
			byte[] bt = decrypt(buf, key.getBytes());
			return new String(bt);
		} catch (Throwable e) {
			throw new RuntimeException(e);
		}
	}

	/**
	 * Description 根据键值进行加密
	 * 
	 * @param data
	 * @param key
	 *            加密键byte数组
	 * @return
	 * @throws Exception
	 */
	private static byte[] encrypt(byte[] data, byte[] key) throws Exception {
		// 生成一个可信任的随机数源
		SecureRandom sr = new SecureRandom();

		// 从原始密钥数据创建DESKeySpec对象
		DESKeySpec dks = new DESKeySpec(key);

		// 创建一个密钥工厂，然后用它把DESKeySpec转换成SecretKey对象
		SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
		SecretKey securekey = keyFactory.generateSecret(dks);

		// Cipher对象实际完成加密操作
		Cipher cipher = Cipher.getInstance(DES);

		// 用密钥初始化Cipher对象
		cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);

		return cipher.doFinal(data);
	}

	/**
	 * Description 根据键值进行解密
	 * 
	 * @param data
	 * @param key
	 *            加密键byte数组
	 * @return
	 * @throws Exception
	 */
	private static byte[] decrypt(byte[] data, byte[] key) throws Exception {
		// 生成一个可信任的随机数源
		SecureRandom sr = new SecureRandom();

		// 从原始密钥数据创建DESKeySpec对象
		DESKeySpec dks = new DESKeySpec(key);

		// 创建一个密钥工厂，然后用它把DESKeySpec转换成SecretKey对象
		SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
		SecretKey securekey = keyFactory.generateSecret(dks);

		// Cipher对象实际完成解密操作
		Cipher cipher = Cipher.getInstance(DES);

		// 用密钥初始化Cipher对象
		cipher.init(Cipher.DECRYPT_MODE, securekey, sr);

		return cipher.doFinal(data);
	}

	public static void main(String[] args) throws Exception {
		// String data = "123 456";
		// String key = "wang!@#$%";
		// System.err.println(encrypt(data, key));
		// System.err.println(decrypt(encrypt(data, key), key));

		String content = "24C2584138719D77C4FEBDE382D84648";
		String password = "12345678";
		System.out.println("密　钥：" + password);
		System.out.println("加密前：" + content);
		// 加密
		String encryptResult = encrypt(content, password);
		System.out.println("加密后：" + encryptResult);
		// 解密
		String decryptResult = decrypt(encryptResult, password);
		System.out.println("解密后：" + decryptResult);

	}
}
